5. Let a, b, and c be positive integers. Use congruence mod 4 to prove the given statement. If $3^a + 4^b = 5^c$, then a must be even.
Added by Charles K.
Close
Step 1
First, let's write down the given statement: a^2 + b^2 + c^2 ≡ 0 (mod 4) To prove this statement using congruence modulo 4, we need to show that the left-hand side (a^2 + b^2 + c^2) is congruent to the right-hand side (0) modulo 4. Show more…
Show all steps
Your feedback will help us improve your experience
Gregory Higby and 63 other Algebra educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Prove that if n is a positive integer and a and b are integers, then ab mod n = [(a mod n)(b mod n)] mod n.
David M.
Prove if a = b mod n and the integers a, b, n are all divisible by d > 0 then a/d = b/d mod n/d.
Sri K.
Shaiju T.
Recommended Textbooks
Elementary and Intermediate Algebra
Algebra and Trigonometry
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD